MOTOROLA Order this document by MRF1518/D SEMICONDUCTOR TECHNICAL DATA The RF MOSFET Line RF Power Field Effect Transistor N-Channel Enhancement-Mode Lateral MOSFET The MRF1518T1 is designed for broadband commercial and industrial applications at frequencies to 520 MHz. The high gain and broadband performance of this device makes it ideal for large-signal, common source amplifier applications in 12.5 volt mobile FM equipment. * Specified Performance @ 520 MHz, 12.5 Volts D Output Power -- 8 Watts Power Gain -- 11 dB Efficiency -- 55% * Capable of Handling 20:1 VSWR, @ 15.5 Vdc, 520 MHz, 2 dB Overdrive * Excellent Thermal Stability * Characterized with Series Equivalent Large-Signal G Impedance Parameters * RF Power Plastic Surface Mount Package * Broadband UHF/VHF Demonstration Amplifier S Information Available Upon Request * Available in Tape and Reel. T1 Suffix = 1,000 Units per 12 mm, 7 Inch Reel. MRF1518T1 520 MHz, 8 W, 12.5 V LATERAL N-CHANNEL BROADBAND RF POWER MOSFET CASE 466-02, STYLE 1 (PLD-1.5) PLASTIC MAXIMUM RATINGS Rating Symbol Value Unit Drain-Source Voltage VDSS 40 Vdc Gate-Source Voltage VGS 20 Vdc Drain Current -- Continuous ID 4 Adc Total Device Dissipation @ TC = 25C (1) Derate above 25C PD 62.5 0.50 Watts W/C Storage Temperature Range Tstg - 65 to +150 C TJ 150 C Symbol Max Unit RJC 2 C/W Operating Junction Temperature THERMAL CHARACTERISTICS Characteristic Thermal Resistance, Junction to Case (1) Calculated based on the formula PD = TJ - TC RJC NOTE - CAUTION - MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and packaging MOS devices should be observed. REV 1 MOTOROLA RF DEVICE DATA Motorola, Inc. 2000 MRF1518T1 1 ELECTRICAL CHARACTERISTICS (TC = 25C unless otherwise noted) Characteristic Symbol Min Typ Max Unit Zero Gate Voltage Drain Current (VDS = 40 Vdc, VGS = 0) IDSS -- -- 1 Adc Gate-Source Leakage Current (VGS = 10 Vdc, VDS = 0) IGSS -- -- 1 Adc Gate Threshold Voltage (VDS = 12.5 Vdc, ID = 100 A) VGS(th) 1.0 1.6 2.1 Vdc Drain-Source On-Voltage (VGS = 10 Vdc, ID = 1 Adc) VDS(on) -- 0.4 -- Vdc Input Capacitance (VDS = 12.5 Vdc, VGS = 0, f = 1 MHz) Ciss -- 66 -- pF Output Capacitance (VDS = 12.5 Vdc, VGS = 0, f = 1 MHz) Coss -- 33 -- pF Reverse Transfer Capacitance (VDS = 12.5 Vdc, VGS = 0, f = 1 MHz) Crss -- 4.5 -- pF Common-Source Amplifier Power Gain (VDD = 12.5 Vdc, Pout = 8 Watts, IDQ = 150 mA, f = 520 MHz) Gps 10 11 -- dB Drain Efficiency (VDD = 12.5 Vdc, Pout = 8 Watts, IDQ = 150 mA, f = 520 MHz) 50 55 -- % OFF CHARACTERISTICS ON CHARACTERISTICS DYNAMIC CHARACTERISTICS FUNCTIONAL TESTS (In Motorola Test Fixture) MRF1518T1 2 MOTOROLA RF DEVICE DATA B2 VGG C8 + C7 C6 R4 B1 C15 C16 R3 + C14 VDD C13 L1 C5 R2 Z6 Z7 Z8 Z9 N2 Z10 RF OUTPUT R1 N1 RF INPUT Z1 Z2 Z3 Z4 Z5 DUT C12 C10 C9 C11 C1 C2 B1, B2 C3 C4 R4 Z1 Z2 Z3 Z4 Z5, Z6 Z7 Z8 Z9 Z10 Board Short Ferrite Bead, Fair Rite Products (2743021446) 240 pF, 100 mil Chip Capacitor 0 to 20 pF, Trimmer Capacitor 82 pF, 100 mil Chip Capacitor 120 pF, 100 mil Chip Capacitor 10 F, 50 V Electrolytic Capacitor 1,200 pF, 100 mil Chip Capacitor 0.1 mF, 100 mil Chip Capacitor 30 pF, 100 mil Chip Capacitor 55.5 nH, 5 Turn, Coilcraft Type N Flange Mount 15 , 0805 Chip Resistor 51 , 1/2 W Resistor 10 , 0805 Chip Resistor C1, C14 C2, C3, C10, C11 C4 C5, C16 C6, C13 C7, C14 C8, C15 C9 L1 N1, N2 R1 R2 R3 33 k, 1/8 W Resistor 0.451 x 0.080 Microstrip 1.005 x 0.080 Microstrip 0.020 x 0.080 Microstrip 0.155 x 0.080 Microstrip 0.260 x 0.223 Microstrip 0.065 x 0.080 Microstrip 0.266 x 0.080 Microstrip 1.113 x 0.080 Microstrip 0.433 x 0.080 Microstrip Glass Teflon, 31 mils, 2 oz. Copper Figure 1. 450 - 520 MHz Broadband Test Circuit TYPICAL CHARACTERISTICS, 450 - 520 MHz 12 0 10 470 MHz IRL, INPUT RETURN LOSS (dB) Pout , OUTPUT POWER (WATTS) VDD = 12.5 V 450 MHz 8 500 MHz 6 520 MHz 4 2 -5 470 MHz -10 450 MHz 500 MHz -15 520 MHz VDD = 12.5 V -20 0 0 0.1 0.3 0.2 0.4 Pin, INPUT POWER (WATTS) 0.5 Figure 2. Output Power versus Input Power MOTOROLA RF DEVICE DATA 0.6 0 1 2 3 4 5 6 7 8 Pout, OUTPUT POWER (WATTS) 9 10 11 Figure 3. Input Return Loss versus Output Power MRF1518T1 3 TYPICAL CHARACTERISTICS, 450 - 520 MHz 17 80 470 MHz 450 MHz GAIN (dB) Eff, DRAIN EFFICIENCY (%) 520 MHz 13 500 MHz 11 9 7 60 50 520 MHz 40 500 MHz 30 20 VDD = 12.5 V 10 VDD = 12.5 V 0 5 0 2 1 3 4 5 6 7 8 Pout, OUTPUT POWER (WATTS) 9 11 10 2 3 4 5 6 7 8 9 Pout, OUTPUT POWER (WATTS) 10 11 12 Figure 5. Drain Efficiency versus Output Power 70 12 470 MHz 65 10 470 MHz Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 1 0 Figure 4. Gain versus Output Power 450 MHz 8 520 MHz 6 500 MHz 4 VDD = 12.5 V Pin = 26.2 dBm 2 450 MHz 60 500 MHz 55 520 MHz 50 45 40 VDD = 12.5 V Pin = 26.2 dBm 35 0 30 0 200 800 400 600 IDQ, BIASING CURRENT (mA) 0 1000 200 Figure 6. Output Power versus Biasing Current 400 600 IDQ, BIASING CURRENT (mA) 1000 800 Figure 7. Drain Efficiency versus Biasing Current 12 80 470 MHz 11 75 450 MHz 10 Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 470 MHz 450 MHz 70 15 9 8 7 6 520 MHz 5 500 MHz 4 8 9 10 11 12 13 14 15 VDD, SUPPLY VOLTAGE (VOLTS) Figure 8. Output Power versus Supply Voltage MRF1518T1 4 470 MHz 65 450 MHz 60 520 MHz 55 500 MHz 50 45 40 IDQ = 150 mA Pin = 26.2 dBm 3 2 70 IDQ = 150 mA Pin = 26.2 dBm 35 30 16 8 9 10 11 12 13 14 15 16 VDD, SUPPLY VOLTAGE (VOLTS) Figure 9. Drain Efficiency versus Supply Voltage MOTOROLA RF DEVICE DATA B2 VGG C10 + C9 C8 B1 R4 C18 R3 C17 + C16 VDD C15 L1 C7 R2 Z7 Z8 Z9 Z10 N2 Z11 R1 N1 Z1 RF INPUT Z2 Z3 Z4 Z5 Z6 DUT C14 C11 C12 RF OUTPUT C13 C1 C2 B1, B2 C1, C14 C2, C3, C4, C11, C12, C13 C5 C6 C7, C18 C8, C15 C9, C16 C10, C17 L1 N1, N2 R1 R2 C3 C4 C5 C6 10 , 0805 Chip Resistor 33 k, 1/8 W Resistor 0.476 x 0.080 Microstrip 0.724 x 0.080 Microstrip 0.348 x 0.080 Microstrip 0.048 x 0.080 Microstrip 0.175 x 0.080 Microstrip 0.260 x 0.223 Microstrip 0.239 x 0.080 Microstrip 0.286 x 0.080 Microstrip 0.806 x 0.080 Microstrip 0.553 x 0.080 Microstrip Glass Teflon, 31 mils, 2 oz. Copper R3 R4 Z1 Z2 Z3 Z4 Z5 Z6, Z7 Z8 Z9 Z10 Z11 Board Short Ferrite Bead, Fair Rite Products (2743021446) 240 pF, 100 mil Chip Capacitor 0 to 20 pF, Trimmer Capacitor 30 pF, 100 mil Chip Capacitor 47 pF, 100 mil Chip Capacitor 120 pF, 100 mil Chip Capacitor 10 F, 50 V Electrolytic Capacitor 1,200 pF, 100 mil Chip Capacitor 0.1 F, 100 mil Chip Capacitor 55.5 nH, 5 Turn, Coilcraft Type N Flange Mount 15 , 0805 Chip Resistor 51 , 1/2 W Resistor Figure 10. 400 - 470 MHz Broadband Test Circuit TYPICAL CHARACTERISTICS, 400 - 470 MHz 12 0 10 IRL, INPUT RETURN LOSS (dB) Pout , OUTPUT POWER (WATTS) 440 MHz 400 MHz 470 MHz 8 6 4 VDD = 12.5 V 2 VDD = 12.5 V -5 440 MHz -10 400 MHz -15 470 MHz 0 -20 0 0.1 0.2 0.3 0.4 0.5 Pin, INPUT POWER (WATTS) 0.6 Figure 11. Output Power versus Input Power MOTOROLA RF DEVICE DATA 0.7 0 1 2 3 4 5 6 7 8 9 Pout, OUTPUT POWER (WATTS) 10 11 12 Figure 12. Input Return Loss versus Output Power MRF1518T1 5 TYPICAL CHARACTERISTICS, 400 - 470 MHz 80 17 70 15 Eff, DRAIN EFFICIENCY (%) GAIN (dB) 13 400 MHz 470 MHz 11 9 VDD = 12.5 V 7 60 400 MHz 50 40 30 20 VDD = 12.5 V 10 5 0 0 5 6 7 8 4 3 9 Pout, OUTPUT POWER (WATTS) 2 1 10 11 0 12 Figure 13. Gain versus Output Power 1 2 10 11 12 70 440 MHz 10 470 MHz 8 6 4 VDD = 12.5 V Pin = 26.8 dBm 2 470 MHz 65 400 MHz Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 5 6 7 8 9 3 4 Pout, OUTPUT POWER (WATTS) Figure 14. Drain Efficiency versus Output Power 12 440 MHz 60 400 MHz 55 50 45 VDD = 12.5 V Pin = 26.8 dBm 40 35 0 30 0 200 400 600 IDQ, BIASING CURRENT (mA) 800 0 1000 400 600 IDQ, BIASING CURRENT (mA) 200 Figure 15. Output Power versus Biasing Current 1000 800 Figure 16. Drain Efficiency versus Biasing Current 12 80 440 MHz 11 75 10 Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 440 MHz 470 MHz 440 MHz 400 MHz 9 8 7 6 470 MHz 5 4 8 9 10 11 12 13 14 VDD, SUPPLY VOLTAGE (VOLTS) Figure 17. Output Power versus Supply Voltage MRF1518T1 6 15 65 470 MHz 60 55 440 MHz 50 400 MHz 45 40 IDQ = 150 mA Pin = 26.8 dBm 3 2 70 IDQ = 150 mA Pin = 26.8 dBm 35 30 16 8 9 10 11 12 13 14 15 16 VDD, SUPPLY VOLTAGE (VOLTS) Figure 18. Drain Efficiency versus Supply Voltage MOTOROLA RF DEVICE DATA B2 VGG C9 + C8 C7 R4 B1 C16 C17 R3 C15 + VDD C14 L4 C6 R2 Z6 RF INPUT Z7 Z8 L3 L2 Z9 RF OUTPUT C13 Z10 R1 L1 Z1 Z2 Z3 Z4 Z5 DUT N2 C12 C10 N1 C1 C11 C4 C3 C5 C2 B1, B2 L4 N1, N2 R1 R2 R3 R4 Z1 Z2 Z3 Z4 Z5, Z6 Z7 Z8 Z9 Z10 Board Short Ferrite Bead, Fair Rite Products (2743021446) 330 pF, 100 mil Chip Capacitor 0 to 20 pF, Trimmer Capacitor 12 pF, 100 mil Chip Capacitor 43 pF, 100 mil Chip Capacitor 75 pF, 100 mil Chip Capacitor 10 F, 50 V Electrolytic Capacitor 1,200 pF, 100 mil Chip Capacitor 0.1 F, 100 mil Chip Capacitor 75 pF, 100 mil Chip Capacitor 13 pF, 100 mil Chip Capacitor 26 nH, 4 Turn, Coilcraft 5 nH, 2 Turn, Coilcraft 33 nH, 5 Turn, Coilcraft C1, C13 C2, C4, C11 C3 C5 C6, C17 C7, C14 C8, C15 C9, C16 C10 C12 L1 L2 L3 55.5 nH, 5 Turn, Coilcraft Type N Flange Mount 15 , 0805 Chip Resistor 56 , 1/4 W Carbon Resistor 100 , 0805 Chip Resistor 33 k , 1/8 W Carbon Resistor 0.115 x 0.080 Microstrip 0.255 x 0.080 Microstrip 1.037 x 0.080 Microstrip 0.192 x 0.080 Microstrip 0.260 x 0.223 Microstrip 0.125 x 0.080 Microstrip 0.962 x 0.080 Microstrip 0.305 x 0.080 Microstrip 0.155 x 0.080 Microstrip Glass Teflon, 31 mils, 2 oz. Copper W W W W Figure 19. 135 - 175 MHz Broadband Test Circuit TYPICAL CHARACTERISTICS, 135 - 175 MHz 0 VDD = 12.5 V 10 IRL, INPUT RETURN LOSS (dB) Pout , OUTPUT POWER (WATTS) 12 8 155 MHz 6 175 MHz 4 135 MHz 2 -5 155 MHz -10 135 MHz 175 MHz -15 VDD = 12.5 V 0 -20 0 0.1 0.2 0.3 Pin, INPUT POWER (WATTS) Figure 20. Output Power versus Input Power MOTOROLA RF DEVICE DATA 0.4 0 1 2 3 4 5 6 7 8 9 Pout, OUTPUT POWER (WATTS) 10 11 12 Figure 21. Input Return Loss versus Output Power MRF1518T1 7 TYPICAL CHARACTERISTICS, 135 - 175 MHz 19 80 135 MHz 70 Eff, DRAIN EFFICIENCY (%) 17 175 MHz GAIN (dB) 15 155 MHz 13 11 9 155 MHz 60 135 MHz 50 175 MHz 40 30 20 VDD = 12.5 V 10 VDD = 12.5 V 0 7 0 2 1 4 3 5 6 7 8 9 Pout, OUTPUT POWER (WATTS) 10 11 12 0 Figure 22. Gain versus Output Power 1 2 11 12 70 175 MHz 155 MHz 135 MHz 65 10 135 MHz 155 MHz Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 10 Figure 23. Drain Efficiency versus Output Power 12 8 6 4 VDD = 12.5 V Pin = 24.5 dBm 2 60 175 MHz 55 50 45 40 VDD = 12.5 V Pin = 24.5 dBm 35 0 30 200 0 800 400 600 IDQ, BIASING CURRENT (mA) 1000 200 0 Figure 24. Output Power versus Biasing Current 800 400 600 IDQ, BIASING CURRENT (mA) 1000 Figure 25. Drain Efficiency versus Biasing Current 12 80 135 MHz 11 75 155 MHz 10 Eff, DRAIN EFFICIENCY (%) Pout , OUTPUT POWER (WATTS) 4 5 7 8 3 9 6 Pout, OUTPUT POWER (WATTS) 175 MHz 9 8 7 6 5 IDQ = 150 mA Pin = 24.5 dBm 4 70 155 MHz 65 135 MHz 60 175 MHz 55 50 45 IDQ = 150 mA Pin = 24.5 dBm 40 3 2 35 30 8 9 10 11 12 13 14 VDD, SUPPLY VOLTAGE (VOLTS) Figure 26. Output Power versus Supply Voltage MRF1518T1 8 15 16 8 9 10 11 12 13 14 15 16 VDD, SUPPLY VOLTAGE (VOLTS) Figure 27. Drain Efficiency versus Supply Voltage MOTOROLA RF DEVICE DATA Zo = 10 f = 470 MHz Zin 520 520 ZOL* f = 450 MHz f = 450 MHz Zin 400 ZOL* f = 470 MHz 175 135 ZOL* 400 Zo = 10 Zin f = 175 MHz f = 135 MHz VDD = 12.5 V, IDQ = 150 mA, Pout = 8 W Zin VDD = 12.5 V, IDQ = 150 mA, Pout = 8 W VDD = 12.5 V, IDQ = 150 mA, Pout = 8 W f MHz Zin ZOL* f MHz Zin ZOL* f MHz Zin ZOL* 450 4.9 +j2.85 6.42 +j3.23 400 4.28 +j2.36 4.41 +j0.67 135 18.31 -j0.76 8.97 +j2.62 470 4.85 +j3.71 4.59 +j3.61 440 6.45 +j5.13 4.14 +j2.53 155 17.72 +j1.85 9.69 +j2.81 500 4.63 +j3.84 4.72 +j3.12 470 5.91 +j3.34 3.92 +j4.02 175 18.06 +j5.23 7.94 +j1.14 520 3.52 +j3.92 3.81 +j3.27 Zin = Complex conjugate of source impedance with parallel 15 resistor and 82 pF capacitor in series with gate. (See Figure 1). ZOL* = Complex conjugate of the load impedance at given output power, voltage, frequency, and D > 50 %. = Complex conjugate of source impedance with parallel 15 resistor and 47 pF capacitor in series with gate. (See Figure 10). ZOL* = Complex conjugate of the load impedance at given output power, voltage, frequency, and D > 50 %. Zin = Complex conjugate of source impedance with parallel 15 resistor and 43 pF capacitor in series with gate. (See Figure 19). ZOL* = Complex conjugate of the load impedance at given output power, voltage, frequency, and D > 50 %. Note: ZOL* was chosen based on tradeoffs between gain, drain efficiency, and device stability. Input Matching Network Output Matching Network Device Under Test Z in Z * OL Figure 28. Series Equivalent Input and Output Impedance MOTOROLA RF DEVICE DATA MRF1518T1 9 Table 1. Common Source Scattering Parameters (VDD = 12.5 Vdc) IDQ = 150 mA S11 S21 S12 S22 f MHz |S11| |S21| |S12| |S22| 50 0.88 -148 18.91 99 0.033 11 0.67 -144 100 0.85 -163 9.40 86 0.033 -6 0.66 -158 200 0.85 -170 4.47 73 0.026 -17 0.69 -162 300 0.87 -171 2.72 64 0.025 -28 0.74 -163 400 0.88 -172 1.85 56 0.021 -21 0.79 -164 500 0.90 -173 1.35 52 0.019 -30 0.83 -165 600 0.92 -173 1.04 47 0.014 -26 0.85 -167 700 0.93 -174 0.83 44 0.015 -39 0.88 -168 800 0.94 -175 0.68 39 0.014 -31 0.90 -169 900 0.94 -175 0.55 36 0.010 -41 0.91 -170 1000 0.96 -176 0.46 30 0.011 -38 0.95 -170 IDQ = 800 mA f MHz S11 S21 S12 S22 50 |S11| 0.90 -159 |S21| 20.80 97 |S12| 0.020 14 |S22| 0.73 -162 100 0.88 -169 10.35 88 0.018 1 0.74 -169 200 0.88 -174 5.09 79 0.017 -9 0.75 -171 300 0.89 -175 3.23 73 0.015 -18 0.77 -171 400 0.89 -175 2.30 67 0.015 -17 0.80 -171 500 0.90 -176 1.74 63 0.014 -22 0.82 -170 600 0.91 -176 1.39 59 0.014 -19 0.83 -171 700 0.92 -176 1.16 55 0.009 -23 0.85 -171 800 0.93 -176 0.96 50 0.011 -14 0.87 -172 900 0.94 -177 0.80 46 0.007 4 0.88 -173 1000 0.94 -177 0.67 41 0.010 -15 0.89 -173 IDQ = 1.5 A f MHz S11 S21 S12 S22 50 |S11| 0.91 -159 |S21| 20.18 97 |S12| 0.015 11 |S22| 0.73 -165 100 0.89 -169 10.05 89 0.016 -5 0.74 -171 200 0.88 -174 4.93 80 0.015 -3 0.75 -172 300 0.89 -175 3.14 73 0.014 -14 0.78 -172 400 0.89 -176 2.24 67 0.014 -20 0.80 -171 500 0.90 -176 1.70 64 0.014 -22 0.82 -170 600 0.92 -176 1.36 59 0.010 -16 0.84 -171 700 0.92 -176 1.13 55 0.013 -10 0.85 -171 800 0.93 -177 0.94 50 0.008 -13 0.87 -172 900 0.94 -177 0.78 46 0.013 -26 0.87 -173 1000 0.94 -178 0.65 41 0.007 8 0.87 -172 MRF1518T1 10 MOTOROLA RF DEVICE DATA APPLICATIONS INFORMATION DESIGN CONSIDERATIONS This device is a common-source, RF power, N-Channel enhancement mode, Lateral Metal-Oxide Semiconductor Field-Effect Transistor (MOSFET). Motorola Application Note AN211A, "FETs in Theory and Practice", is suggested reading for those not familiar with the construction and characteristics of FETs. This surface mount packaged device was designed primarily for VHF and UHF portable power amplifier applications. Manufacturability is improved by utilizing the tape and reel capability for fully automated pick and placement of parts. However, care should be taken in the design process to insure proper heat sinking of the device. The major advantages of Lateral RF power MOSFETs include high gain, simple bias systems, relative immunity from thermal runaway, and the ability to withstand severely mismatched loads without suffering damage. MOSFET CAPACITANCES The physical structure of a MOSFET results in capacitors between all three terminals. The metal oxide gate structure determines the capacitors from gate-to-drain (Cgd), and gate-to-source (Cgs). The PN junction formed during fabrication of the RF MOSFET results in a junction capacitance from drain-to-source (Cds). These capacitances are characterized as input (Ciss), output (Coss) and reverse transfer (Crss) capacitances on data sheets. The relationships between the inter-terminal capacitances and those given on data sheets are shown below. The Ciss can be specified in two ways: 1. Drain shorted to source and positive voltage at the gate. 2. Positive voltage of the drain in respect to source and zero volts at the gate. In the latter case, the numbers are lower. However, neither method represents the actual operating conditions in RF applications. Drain Cgd Gate Cds Ciss = Cgd + Cgs Coss = Cgd + Cds Crss = Cgd Cgs Source DRAIN CHARACTERISTICS One critical figure of merit for a FET is its static resistance in the full-on condition. This on-resistance, RDS(on), occurs in the linear region of the output characteristic and is specified at a specific gate-source voltage and drain current. The drain-source voltage under these conditions is termed VDS(on). For MOSFETs, VDS(on) has a positive temperature MOTOROLA RF DEVICE DATA coefficient at high temperatures because it contributes to the power dissipation within the device. BVDSS values for this device are higher than normally required for typical applications. Measurement of BVDSS is not recommended and may result in possible damage to the device. GATE CHARACTERISTICS The gate of the RF MOSFET is a polysilicon material, and is electrically isolated from the source by a layer of oxide. The DC input resistance is very high - on the order of 109 -- resulting in a leakage current of a few nanoamperes. Gate control is achieved by applying a positive voltage to the gate greater than the gate-to-source threshold voltage, VGS(th). Gate Voltage Rating -- Never exceed the gate voltage rating. Exceeding the rated VGS can result in permanent damage to the oxide layer in the gate region. Gate Termination -- The gates of these devices are essentially capacitors. Circuits that leave the gate open-circuited or floating should be avoided. These conditions can result in turn-on of the devices due to voltage build-up on the input capacitor due to leakage currents or pickup. Gate Protection -- These devices do not have an internal monolithic zener diode from gate-to-source. If gate protection is required, an external zener diode is recommended. Using a resistor to keep the gate-to-source impedance low also helps dampen transients and serves another important function. Voltage transients on the drain can be coupled to the gate through the parasitic gate-drain capacitance. If the gate-to-source impedance and the rate of voltage change on the drain are both high, then the signal coupled to the gate may be large enough to exceed the gate-threshold voltage and turn the device on. DC BIAS Since this device is an enhancement mode FET, drain current flows only when the gate is at a higher potential than the source. RF power FETs operate optimally with a quiescent drain current (IDQ), whose value is application dependent. This device was characterized at IDQ = 150 mA, which is the suggested value of bias current for typical applications. For special applications such as linear amplification, IDQ may have to be selected to optimize the critical parameters. The gate is a dc open circuit and draws no current. Therefore, the gate bias circuit may generally be just a simple resistive divider network. Some special applications may require a more elaborate bias system. GAIN CONTROL Power output of this device may be controlled to some degree with a low power dc control signal applied to the gate, thus facilitating applications such as manual gain control, ALC/AGC and modulation systems. This characteristic is very dependent on frequency and load line. MRF1518T1 11 MOUNTING The specified maximum thermal resistance of 2C/W assumes a majority of the 0.065 x 0.180 source contact on the back side of the package is in good contact with an appropriate heat sink. As with all RF power devices, the goal of the thermal design should be to minimize the temperature at the back side of the package. Refer to Motorola Application Note AN4005/D, "Thermal Management and Mounting Method for the PLD-1.5 RF Power Surface Mount Package," and Engineering Bulletin EB209/D, "Mounting Method for RF Power Leadless Surface Mount Transistor" for additional information. AMPLIFIER DESIGN Impedance matching networks similar to those used with bipolar transistors are suitable for this device. For examples see Motorola Application Note AN721, "Impedance Matching Networks Applied to RF Power Transistors." Large-signal MRF1518T1 12 impedances are provided, and will yield a good first pass approximation. Since RF power MOSFETs are triode devices, they are not unilateral. This coupled with the very high gain of this device yields a device capable of self oscillation. Stability may be achieved by techniques such as drain loading, input shunt resistive loading, or output to input feedback. The RF test fixture implements a parallel resistor and capacitor in series with the gate, and has a load line selected for a higher efficiency, lower gain, and more stable operating region. Two-port stability analysis with this device's S-parameters provides a useful tool for selection of loading or feedback circuitry to assure stable operation. See Motorola Application Note AN215A, "RF Small-Signal Design Using Two-Port Parameters" for a discussion of two port network theory and stability. MOTOROLA RF DEVICE DATA NOTES MOTOROLA RF DEVICE DATA MRF1518T1 13 NOTES MRF1518T1 14 MOTOROLA RF DEVICE DATA NOTES MOTOROLA RF DEVICE DATA MRF1518T1 15 PACKAGE DIMENSIONS L R C 2 A F N K S ZONE V 0.095 2.41 0.115 2.92 H G 1 D B Q 0.146 3.71 U ZONE X 4 3 EEEE EEEE EEEE EEEE EEEE EEEE EEE EEE 10_DRAFT P ZONE W 0.115 2.92 0.020 0.51 J E 0.89 (0.035) X 45 _ "5 _ RESIN BLEED/FLASH ALLOWABLE inches mm SOLDER FOOTPRINT STYLE 1: PIN 1. 2. 3. 4. DRAIN GATE SOURCE SOURCE NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH 3. RESIN BLEED/FLASH ALLOWABLE IN ZONE V, W, AND X. CASE 466-02 ISSUE B DIM A B C D E F G H J K L N P Q R S U ZONE V ZONE W ZONE X INCHES MIN MAX 0.255 0.265 0.225 0.235 0.065 0.072 0.130 0.150 0.021 0.026 0.026 0.044 0.050 0.070 0.045 0.063 0.160 0.180 0.273 0.285 0.245 0.255 0.230 0.240 0.000 0.008 0.055 0.063 0.200 0.210 0.006 0.012 0.006 0.012 0.000 0.021 0.000 0.010 0.000 0.010 MILLIMETERS MIN MAX 6.48 6.73 5.72 5.97 1.65 1.83 3.30 3.81 0.53 0.66 0.66 1.12 1.27 1.78 1.14 1.60 4.06 4.57 6.93 7.24 6.22 6.48 5.84 6.10 0.00 0.20 1.40 1.60 5.08 5.33 0.15 0.31 0.15 0.31 0.00 0.53 0.00 0.25 0.00 0.25 Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. Mfax is a trademark of Motorola, Inc. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 5405, Denver, Colorado 80217. 1-303-675-2140 or 1-800-441-2447 JAPAN: Motorola Japan Ltd.; SPS, Technical Information Center, 3-20-1, Minami-Azabu. Minato-ku, Tokyo 106-8573 Japan. 81-3-3440-3569 Customer Focus Center: 1-800-521-6274 Mfax: RMFAX0@email.sps.mot.com - TOUCHTONE 1-602-244-6609 ASIA / PACIFIC: Motorola Semiconductors H.K. Ltd.; Silicon Harbour Centre, Motorola Fax Back System - US & Canada ONLY 1-800-774-1848 2, Dai King Street, Tai Po Industrial Estate, Tai Po, N.T., Hong Kong. - http://sps.motorola.com/mfax/ 852-26668334 HOME PAGE: http://www.motorola.com/semiconductors/ MRF1518T1 16 MOTOROLA RF DEVICEMRF1518/D DATA